package com.yjd.comm.util;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.*;
import java.util.HashMap;
import java.util.Map;


@SuppressWarnings("rawtypes")
public class ReflectionUtils {

    private static final String SETTER_PREFIX = "set";

    private static final String GETTER_PREFIX = "get";

    private static final String CGLIB_CLASS_SEPARATOR = "$$";

    private static Logger logger = LoggerFactory.getLogger(ReflectionUtils.class);

    public static Object invokeGetMethod(Class<?> claszz, Object o, String name) {
        Object ret = null;
        try {
            Method method = claszz.getMethod("get" +  StringUtil.firstCharUpperCase(name));
            ret = method.invoke(o);
        } catch (Exception e) {
            logger.error(e.getMessage(),e);
        }
        return ret;
    }


    /**
     * 调用Getter方法.
     * 支持多级，如：对象名.对象名.方法
     */
    public static Object invokeGetter(Object obj, String propertyName) {
        Object object = obj;
        for (String name : StringUtils.split(propertyName, ".")){
            String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(name);
            object = invokeMethod(object, getterMethodName, new Class[] {}, new Object[] {});
        }
        return object;
    }

    /**
     * 调用Setter方法, 仅匹配方法名。
     * 支持多级，如：对象名.对象名.方法
     */
    public static void invokeSetter(Object obj, String propertyName, Object value) {
        Object object = obj;
        String[] names = StringUtils.split(propertyName, ".");
        for (int i=0; i<names.length; i++){
            if(i<names.length-1){
                String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(names[i]);
                object = invokeMethod(object, getterMethodName, new Class[] {}, new Object[] {});
            }else{
                String setterMethodName = SETTER_PREFIX + StringUtils.capitalize(names[i]);
                invokeMethodByName(object, setterMethodName, new Object[] { value });
            }
        }
    }

    /**
     * 调用Setter方法(赋值)
     * @param claszz
     * @param o
     * @param name
     * @param argType
     * @param args
     * @return
     */
    public static Object invokeSetter(Class<?> claszz, Object o, String name, Class<?> argType, Object args) {
        Object ret = null;
        try {
            // 非 常量 进行反射
            if (!checkModifiers(claszz, name)) {
                Method method = claszz.getMethod("set" + StringUtil.firstCharUpperCase(name), new Class[] { argType });
                ret = method.invoke(o, new Object[] { args });
            }
        } catch (Exception e) {
            logger.error("claszz:{},name:{},argType:{},args:{}",claszz,name,argType, args);
        }
        return ret;
    }

    /**
     * 直接读取对象属性值, 无视private/protected修饰符, 不经过getter函数.
     */
    public static Object getFieldValue(final Object obj, final String fieldName) {
        Field field = getAccessibleField(obj, fieldName);

        if (field == null) {
            throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
        }

        Object result = null;
        try {
            result = field.get(obj);
        } catch (IllegalAccessException e) {
            logger.error("不可能抛出的异常{}", e.getMessage());
        }
        return result;
    }

    /**
     * 直接设置对象属性值, 无视private/protected修饰符, 不经过setter函数.
     */
    public static void setFieldValue(final Object obj, final String fieldName, final Object value) {
        Field field = getAccessibleField(obj, fieldName);

        if (field == null) {
            throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
        }

        try {
            field.set(obj, value);
        } catch (IllegalAccessException e) {
            logger.error("不可能抛出的异常:{}", e.getMessage());
        }
    }

    /**
     * 直接调用对象方法, 无视private/protected修饰符.
     * 用于一次性调用的情况，否则应使用getAccessibleMethod()函数获得Method后反复调用.
     * 同时匹配方法名+参数类型，
     */
    public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes,
                                      final Object[] args) {
        Method method = getAccessibleMethod(obj, methodName, parameterTypes);
        if (method == null) {
            throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
        }

        try {
            return method.invoke(obj, args);
        } catch (Exception e) {
            throw convertReflectionExceptionToUnchecked(e);
        }
    }

    /**
     * 直接调用对象方法, 无视private/protected修饰符，
     * 用于一次性调用的情况，否则应使用getAccessibleMethodByName()函数获得Method后反复调用.
     * 只匹配函数名，如果有多个同名函数调用第一个。
     */
    public static Object invokeMethodByName(final Object obj, final String methodName, final Object[] args) {
        Method method = getAccessibleMethodByName(obj, methodName);
        if (method == null) {
            throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
        }

        try {
            return method.invoke(obj, args);
        } catch (Exception e) {
            throw convertReflectionExceptionToUnchecked(e);
        }
    }

    /**
     * 循环向上转型, 获取对象的DeclaredField, 并强制设置为可访问.
     *
     * 如向上转型到Object仍无法找到, 返回null.
     */
    public static Field getAccessibleField(final Object obj, final String fieldName) {
        Validate.notNull(obj, "object can't be null");
        Validate.notBlank(fieldName, "fieldName can't be blank");
        for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
            try {
                Field field = superClass.getDeclaredField(fieldName);
                makeAccessible(field);
                return field;
            } catch (NoSuchFieldException e) {//NOSONAR
                // Field不在当前类定义,继续向上转型
                continue;// new add
            }
        }
        return null;
    }

    /**
     * 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问.
     * 如向上转型到Object仍无法找到, 返回null.
     * 匹配函数名+参数类型。
     *
     * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
     */
    public static Method getAccessibleMethod(final Object obj, final String methodName,
                                             final Class<?>... parameterTypes) {
        Validate.notNull(obj, "object can't be null");
        Validate.notBlank(methodName, "methodName can't be blank");

        for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
            try {
                Method method = searchType.getDeclaredMethod(methodName, parameterTypes);
                makeAccessible(method);
                return method;
            } catch (NoSuchMethodException e) {
                // Method不在当前类定义,继续向上转型
                continue;// new add
            }
        }
        return null;
    }

    /**
     * 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问.
     * 如向上转型到Object仍无法找到, 返回null.
     * 只匹配函数名。
     *
     * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
     */
    public static Method getAccessibleMethodByName(final Object obj, final String methodName) {
        Validate.notNull(obj, "object can't be null");
        Validate.notBlank(methodName, "methodName can't be blank");

        for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
            Method[] methods = searchType.getDeclaredMethods();
            for (Method method : methods) {
                if (method.getName().equals(methodName)) {
                    makeAccessible(method);
                    return method;
                }
            }
        }
        return null;
    }

    /**
     * 改变private/protected的方法为public，尽量不调用实际改动的语句，避免JDK的SecurityManager抱怨。
     */
    public static void makeAccessible(Method method) {
        if ((!Modifier.isPublic(method.getModifiers()) || !Modifier.isPublic(method.getDeclaringClass().getModifiers()))
                && !method.isAccessible()) {
            method.setAccessible(true);
        }
    }

    /**
     * 改变private/protected的成员变量为public，尽量不调用实际改动的语句，避免JDK的SecurityManager抱怨。
     */
    public static void makeAccessible(Field field) {
        if ((!Modifier.isPublic(field.getModifiers()) || !Modifier.isPublic(field.getDeclaringClass().getModifiers()) || Modifier
                .isFinal(field.getModifiers())) && !field.isAccessible()) {
            field.setAccessible(true);
        }
    }

    /**
     * 通过反射, 获得Class定义中声明的泛型参数的类型, 注意泛型必须定义在父类处
     * 如无法找到, 返回Object.class.
     * eg.
     * public UserDao extends HibernateDao<User>
     *
     * @param clazz The class to introspect
     * @return the first generic declaration, or Object.class if cannot be determined
     */
    @SuppressWarnings("unchecked")
    public static <T> Class<T> getClassGenricType(final Class clazz) {
        return getClassGenricType(clazz, 0);
    }

    /**
     * 通过反射, 获得Class定义中声明的父类的泛型参数的类型.
     * 如无法找到, 返回Object.class.
     *
     * 如public UserDao extends HibernateDao<User,Long>
     *
     * @param clazz clazz The class to introspect
     * @param index the Index of the generic ddeclaration,start from 0.
     * @return the index generic declaration, or Object.class if cannot be determined
     */
    public static Class getClassGenricType(final Class clazz, final int index) {

        Type genType = clazz.getGenericSuperclass();

        if (!(genType instanceof ParameterizedType)) {
            logger.warn("{}'s superclass not ParameterizedType",clazz.getSimpleName());
            return Object.class;
        }

        Type[] params = ((ParameterizedType) genType).getActualTypeArguments();

        if (index >= params.length || index < 0) {
            logger.warn("Index: {}, Size of {}'s Parameterized Type: {}",index,clazz.getSimpleName(), params.length);
            return Object.class;
        }
        if (!(params[index] instanceof Class)) {
            logger.warn(" {} not set the actual class on superclass generic parameter",clazz.getSimpleName());
            return Object.class;
        }

        return (Class) params[index];
    }

    public static Class<?> getUserClass(Object instance) {
        if(instance == null){
            throw new RuntimeException("Instance must not be null");
        }
        Class clazz = instance.getClass();
        if (clazz != null && clazz.getName().contains(CGLIB_CLASS_SEPARATOR)) {
            Class<?> superClass = clazz.getSuperclass();
            if (superClass != null && !Object.class.equals(superClass)) {
                return superClass;
            }
        }
        return clazz;

    }

    /**
     * 取得类中某个Field的类型名称
     * @param clazz
     * @param fieldName
     * @return
     */
    public static String getFieldTypeName(final Class clazz, String fieldName) {
        Field field = null;
        Class tclazz = clazz;
        do {
            try {
                field = tclazz.getDeclaredField(fieldName);
            } catch (NoSuchFieldException e) {
                tclazz = clazz.getSuperclass();
            } catch (SecurityException e) {
            }

        } while (tclazz != Object.class && field == null);

        return (field == null)?null:field.getType().getSimpleName();
    }

    /**
     * 将反射时的checked exception转换为unchecked exception.
     */
    public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) {
        if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException
                || e instanceof NoSuchMethodException) {
            return new IllegalArgumentException(e);
        } else if (e instanceof InvocationTargetException) {
            return new RuntimeException(((InvocationTargetException) e).getTargetException());
        } else if (e instanceof RuntimeException) {
            return (RuntimeException) e;
        }
        return new RuntimeException("Unexpected Checked Exception.", e);
    }

    /**
     * object 属性名称及属性值组装为String字符串。
     * 组装规则：
     * field.name1=field.value1&field.name2=field.value2 ...
     * @param object
     * @return
     */
    public static String objToString(Object object) {
        Class<?> clazz = object.getClass();
        Field[] fss = new Field[0];
        for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
            try {
                Field[] fs = clazz.getDeclaredFields();
                fss = ArrayUtils.addAll(fss, fs);
            } catch (Exception e) {
                // 这里异常不能抛出去。
                // 如果这里的异常打印或者往外抛，就不会执行clazz = clazz.getSuperclass(),
                // 最后就不会进入到父类中了
            }
        }
        StringBuffer sb = new StringBuffer(50);
        for (Field f : fss) {
            // 反射对象中String类型，且不为常量的字段
            if (String.class.equals(f.getType()) && !isConstant(f.getModifiers())) {
                String fieldName = f.getName();
                Object o = invokeGetMethod(f.getDeclaringClass(), object, fieldName);
                String value = null==o?"":o.toString();
                if (value == "") {
                    continue;
                }
                sb.append(fieldName + "=" + value + "&");
            }
        }
        logger.info("请求参数："+sb.toString());
        return sb.toString();
    }

    /**
     * 是否为常量
     * @param modifiers
     * @return 常量返回true，非常量返回false
     */
    private static boolean isConstant(int modifiers) {
        // static 和 final修饰
        if (Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers)) {
            return true;
        }
        return false;
    }

    /**
     * 校验参数类型
     * 目前只校验是否为 常量
     * @param claszz
     * @param name
     * @return 常量返回true，非常量返回false
     */
    private static boolean checkModifiers(Class<?> claszz, String name) {
        try {
            Field field = claszz.getField(name);
            if (isConstant(field.getModifiers())) {
                return true;
            }
        } catch (NoSuchFieldException | SecurityException e) {
            return false;
        }
        return false;
    }

    /**
     * 取得属性
     * @param clazz
     * @return
     */
    public static Map<String, Field> getClassField(Class<?> clazz) {
        Field[] declaredFields = clazz.getDeclaredFields();
        Map<String, Field> fieldMap = new HashMap<String, Field>();
        Map<String, Field> superFieldMap = new HashMap<String, Field>();
        for (Field field : declaredFields) {
            fieldMap.put(field.getName(), field);
        }
        if (clazz.getSuperclass() != null) {
            superFieldMap = getClassField(clazz.getSuperclass());
        }
        fieldMap.putAll(superFieldMap);
        return fieldMap;
    }

}